package com.css.fxfzfxqh.modules.buildingKilometerGrid.utils;

import java.io.*;
import java.net.URLEncoder;
import java.util.List;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

import javax.servlet.http.HttpServletResponse;

public class ExportZipUtils {
    /**
     * 导出
     * @param response
     * @param files 要进行压缩的文件数组
     * @param fileNames 压缩的文件要修改成别的名子数组
     * @param zipName 压缩包名称
     * @return zip文件
     *
     */
    public static void createZipFile(HttpServletResponse response, File [] files,List<String> fileNames,String zipName)  {
       // 输出响应
        ZipOutputStream zipStream = null;
        response.setContentType("application/x-zip-compressed");
        response.setHeader("Cache-Control", "max-age=0");
        try {
            response.setHeader("Content-Disposition", "attchment;filename=" + URLEncoder.encode(zipName+".zip", "UTF-8"));
            response.setHeader("Access-Control-Allow-Origin", "*");
            response.setHeader("Access-Control-Allow-Method", "POST,GET");
            //1：定义为输出流
            OutputStream os = response.getOutputStream();
            //2.把输出流给压缩流
            zipStream = new ZipOutputStream(os);
            //3.把file文件，和要修改的名称 循环写入到 FileInputStream 输入流里面
            for (int i=0;i<  files.length;i++){
                File file=files[i];
                compressZip(file, zipStream, fileNames.get(0).split("\\.")[0]);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }finally {
            try {
                if (zipStream != null) {
                    zipStream.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
   
    private static void compressZip(File file, ZipOutputStream zipStream,String alias) throws Exception{
        FileInputStream input = null;
        try {
            //3.1.把file文件 写入到 FileInputStream 输入流里面
            input = new FileInputStream(file);
            //3.2.把 FileInputStream 输入流 写入到 byte[] 字节中
            zip(input, zipStream, alias+"."+file.getName().substring(file.getName().lastIndexOf(".")+1));
        } catch (Exception e) {
            e.printStackTrace();
        }finally {
            try {
                if(input != null)
                    input.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    private static void zip(InputStream input, ZipOutputStream zipStream, String zipEntryName) throws Exception{
        //byte[] 字节
        byte[] bytes = null;
        BufferedInputStream bufferStream = null;
        try {
            if(input == null) {
                throw new Exception("获取压缩的数据项失败! 数据项名为：" + zipEntryName);
            }
            // 压缩条目不是具体独立的文件，而是压缩包文件列表中的列表项，称为条目，就像索引一样
            ZipEntry zipEntry = new ZipEntry(zipEntryName);
            // 定位到该压缩条目位置，开始写入文件到压缩包中
            zipStream.putNextEntry(zipEntry);
            bytes = new byte[1024 * 5];// 读写缓冲区
            bufferStream = new BufferedInputStream(input);// 输入缓冲流
            int read = 0;
            while ((read = bufferStream.read(bytes)) != -1) {
            	//压缩输出流写入bytes[] 数据
                zipStream.write(bytes, 0, read);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (null != bufferStream)
                    bufferStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

}

